Now I quite agree that mankind, thus provided, would live and act according to knowledge, for wisdom would watch and prevent ignorance from intruding on us in our work. But whether by acting according to knowledge we shall act well and be happy, my dear Critias—this is a point which we have not yet been able to determine.
Here (173c-d), the peculiar problems with the form of self-knowledge under discussion in the Charmides give way to a general, intuitive problem that will occupy Plato for much of his career: how can we say for certain that there is a link between knowledge and happiness? Up until this section of the dialogue, temperance as self-knowledge has been discussed in terms of an abstract "knowledge of knowledge," which has obvious problems in terms of its causal relation to concrete goods. Socrates conjures up the perfect, wisdom- governed state partly in order to show up these problems. Here, however, the difficulty has shifted somewhat. Instead of making specific attacks on the particular idea of "knowledge of knowledge," Socrates admits to an anxiety that knowledge of any kind will not necessarily lead to happiness.